Air-conditioning apparatus and evacuation method in air-conditioning apparatus

An air-conditioning apparatus capable of performing a simultaneous cooling and heating operation, comprising:

• an outdoor unit having a compressor, an outdoor heat exchanger configured to exchange heat between an outdoor air and refrigerant, and a flow switching device;
• a plurality of indoor units each having an indoor heat exchanger configured to exchange heat between an air to be air-conditioned and the refrigerant;
• a relay unit provided between the outdoor unit and the plurality of indoor units, and configured to switch a flow of the refrigerant supplied from the outdoor unit to the indoor units;
• and
• a refrigerant circuit formed by connecting the outdoor unit, the plurality of indoor units, and the relay unit by a refrigerant pipe;
• wherein
• the relay unit includes
• a first pathway formed by a first pipe and configured to allow the refrigerant to flow from the plurality of indoor units to the relay unit,
• a first opening and closing device provided in the first pathway and configured to individually block or pass each stream of the refrigerant flowing from a corresponding one of the plurality of indoor units toward the relay unit,
• a second pathway formed by a second pipe and configured to allow the refrigerant to flow from the relay unit to the plurality of indoor units,
• a second opening and closing device provided in the second pathway and configured to individually block or pass each stream of the refrigerant being divided flowing from the relay unit toward a corresponding one of the plurality of indoor units,
• a third pathway formed by a third pipe and configured to allow the refrigerant to flow from the plurality of indoor units to the relay unit,
• a fourth pathway formed by a fourth pipe and configured to allow the refrigerant to flow from the relay unit to the plurality of indoor units,
• a first shutoff device configured to open in a non-energized state to allow a flow of the refrigerant in the fourth pathway and close in an energized state to block a flow of the refrigerant in the fourth pathway, and
• an opening and closing device for evacuation configured to open in a non-energized state to allow a flow of the refrigerant in at least one of the first pathway, the second pathway, the third pathway, and the fourth pathway, and close in an energized state to block a flow of the refrigerant in the at least one of pathways.